Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

pkg/setting/adapters.go

@@ -0,0 +1,133 @@
+package setting
+
+import (
+	"context"
+	"github.com/cloudreve/Cloudreve/v4/inventory"
+	"github.com/cloudreve/Cloudreve/v4/pkg/cache"
+	"github.com/cloudreve/Cloudreve/v4/pkg/conf"
+	"github.com/cloudreve/Cloudreve/v4/pkg/logging"
+	"github.com/samber/lo"
+	"os"
+	"strings"
+)
+
+const (
+	KvSettingPrefix           = "setting_"
+	EnvSettingOverwritePrefix = "CR_SETTING_"
+)
+
+// SettingStoreAdapter chains a setting get operation, if current adapter cannot locate setting value,
+// it will invoke next adapter until last one.
+type SettingStoreAdapter interface {
+	// Get a string setting from underlying store, if setting not found, default
+	// value will be used.
+	Get(ctx context.Context, name string, defaultVal any) any
+}
+
+// NewDbSettingStore creates an adapter using DB setting store. Only string type value is supported.
+func NewDbSettingStore(c inventory.SettingClient, next SettingStoreAdapter) SettingStoreAdapter {
+	return &dbSettingStore{
+		c:    c,
+		next: next,
+	}
+}
+
+// NewKvSettingStore creates an adapter using KV setting store.
+func NewKvSettingStore(c cache.Driver, next SettingStoreAdapter) SettingStoreAdapter {
+	return &kvSettingStore{
+		kv:   c,
+		next: next,
+	}
+}
+
+// NewConfSettingStore creates an adapter using static config overwrite. Only string type value is supported.
+func NewConfSettingStore(c conf.ConfigProvider, next SettingStoreAdapter) SettingStoreAdapter {
+	return &staticSettingStore{
+		settings: c.OptionOverwrite(),
+		next:     next,
+	}
+}
+
+// NewDbDefaultStore creates an adapter that always returns default setting value defined in inventory.DefaultSettings.
+// Only string type value is supported.
+func NewDbDefaultStore(next SettingStoreAdapter) SettingStoreAdapter {
+	return &staticSettingStore{
+		settings: lo.MapValues(inventory.DefaultSettings, func(v string, _ string) any {
+			return v
+		}),
+		next: next,
+	}
+}
+
+// NewEnvOverwriteStore creates an adapter that always returns overrided setting value defined in environment variables.
+func NewEnvOverrideStore(next SettingStoreAdapter, l logging.Logger) SettingStoreAdapter {
+	allEnv := os.Environ()
+	defaults := make(map[string]any)
+	for _, env := range allEnv {
+		kv := strings.SplitN(env, "=", 2)
+		if strings.HasPrefix(kv[0], EnvSettingOverwritePrefix) {
+			key := strings.TrimPrefix(kv[0], EnvSettingOverwritePrefix)
+			defaults[key] = kv[1]
+			l.Info("Override setting %q with value %q from environment", key, kv[1])
+		}
+	}
+
+	return &staticSettingStore{
+		settings: defaults,
+		next:     next,
+	}
+}
+
+type dbSettingStore struct {
+	c    inventory.SettingClient
+	next SettingStoreAdapter
+}
+
+func (s *dbSettingStore) Get(ctx context.Context, name string, defaultVal any) any {
+	if val, err := s.c.Get(ctx, name); err == nil {
+		return val
+	}
+
+	if s.next != nil {
+		return s.next.Get(ctx, name, defaultVal)
+	}
+
+	return defaultVal
+}
+
+type kvSettingStore struct {
+	kv   cache.Driver
+	next SettingStoreAdapter
+}
+
+func (s *kvSettingStore) Get(ctx context.Context, name string, defaultVal any) any {
+	if val, exist := s.kv.Get(KvSettingPrefix + name); exist {
+		return val
+	}
+
+	if s.next != nil {
+		nextVal := s.next.Get(ctx, name, defaultVal)
+		// cache setting value
+		s.kv.Set(KvSettingPrefix+name, nextVal, 0)
+		return nextVal
+	}
+
+	return defaultVal
+}
+
+type staticSettingStore struct {
+	settings map[string]any
+	next     SettingStoreAdapter
+}
+
+func (s *staticSettingStore) Get(ctx context.Context, name string, defaultVal any) any {
+	if val, ok := s.settings[name]; ok {
+		return val
+	}
+
+	if s.next != nil {
+		return s.next.Get(ctx, name, defaultVal)
+	}
+
+	return defaultVal
+}